Viessmann VITOTRONIC 100 Installation And Service Instructions Manual page 79

External hook−up in multi−boiler systems without LON
Adjustments on every control unit
Set code "01: 3"
code "02: 1"
(delivered condition)
The high limit safety cut−out settings
and other settings are subject to the
system equipment and the safety
equipment in accordance with
DIN 4751 2.
Enable boiler, butterfly valve
Contact closed:
Initially, the pre−heat function for lag
boilers is activated. After the
pre−heat function has expired, the
minimum boiler water temperature
will be maintained, and the burner
stages can be controlled externally.
Contact opened:
The butterfly valve is closed after
approx. 5 min. Burner stages cannot
be switched ON externally; a
minimum temperature will not be
maintained.
Starting burner stage 1
Contact closed:
Burner stage 1 is started. Full load is
switched ON only for maintaining
the minimum temperature. The
boiler water temperature is limited
by the electronic maximum
temperature limiter, if it is set below
that of mechanical control
thermostat "R".
Contact opened:
Burner stage 1 is shut down.
Installation
(cont.)
79